<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>

<div id="app">
  <!--1.直接拼接，语法过于繁琐-->
  <h2>{{firstName}} {{lastName}}</h2>
  <!--2.通过定义methods方法: 会执行两次-->
  <h2>{{getFullName()}}</h2>
  <h2>{{getFullName()}}</h2>
  <!--3.通过computed计算属性：有缓存，两个同样的结果，它只会执行一次-->
  <h2>{{fullName}}</h2>
  <h2>{{fullName}}</h2>
</div>

<script src="../js/vue.js"></script>
<script>
  const app=new Vue({
    el: '#app',
    data: {
      firstName:'zhou',
      lastName:'ziShu'
    },
    methods:{
      getFullName:function(){
        console.log('getFullName');
        return this.firstName + ' ' + this.lastName
      }
    },
    computed:{
      fullName:function(){
        console.log('fullName');
        return this.firstName + ' ' + this.lastName
      }
    }
  })

</script>
</body>
</html>